Transmit/receive switching means in hearing aids, such as disclosed in American patent application no.: US 2005/111682, are used for providing switching between transmit and receive modes in hearing aids for wireless communication. This American patent application describes a system wherein an inductive coil operating as an antenna is switched between an equivalent series resonant circuit reducing inductive load in transmit mode and an equivalent parallel resonant circuit increasing inductive load in the receive mode. The system further utilises a transmit/receive-switch to establish a voltage protection during the transmit mode of a low noise amplifier (LNA) used for amplifying received data during the receive mode.
Despite the advances achieved within the hearing aid technology by the above described transmit-receive switching means there still is a need for providing improvements of the noise rejection during receive mode, improvements of the voltage protective elements, and provide means for switching between transmit and receive mode without changing the antenna matching.